docstr: Converts self._exec_properties['custom_config'] to string.
docstr_tok: ["Converts","self._exec_properties","[","'custom_config","'","]","to","string","."]
code: def _serialize_custom_config_under_test(self) -> Dict[str, Any]:
      """Converts self._exec_properties['custom_config'] to string."""
      result = copy.deepcopy(self._exec_properties)
      result[
          standard_component_specs.CUSTOM_CONFIG_KEY
      ] = json_utils.dumps(
          result[standard_component_specs.CUSTOM_CONFIG_KEY]
      )
      return result
  
file_path: tfx/tfx/extensions/google_cloud_ai_platform/trainer/executor_test.py
imports: import copy
  import os
  from typing import Any, Dict
  from unittest import mock
  import tensorflow
  from tfx.components.trainer import executor
  from tfx.extensions.google_cloud_ai_platform.trainer import executor
  from tfx.types import standard_component_specs
  from tfx.utils import json_utils
  from tfx.utils import name_utils
label_desc: Use image node_id 2 for calling the ExecutorTest obj's underlying member method code with example usage: obj._serialize_custom_config_under_test() and returns: result